This document relates to label-free sensing of chemical and biological materials and applications of such label-free sensing.
Various sequencing techniques use a label to attach to a molecule and the labeled molecule is monitored and interrogated to identify which base has been added or removed from a strand of nucleic acid (NA). Such labeling can be achieved by various labeling techniques, including molecular labeling based on radioactivity, fluorescence, and chemiluminescence. However, a label may cause undesired effects, such as altering the molecular binding kinetics, interfering with the accuracy of the reaction, and limiting the length of a contiguous readout, and may require multiple readouts to construct a high confidence sequence. In addition, molecular labeling may require numerous processing steps such as label attachment, washing, label removal, scanning, etc. and thus could complicate the process, require extended time for processing and add significant cost.